International Journal of Organ Transplantation Medicine Changing Pattern of Organ Donation and Utilization in the Usa

AbsTrAcT Background: Organ transplantation has proven highly effective in the treatment of various forms of end-stage organ failure. However, organ shortage is still the greatest challenge facing the field of organ trans-plantation.

R. F. Saidi effort to expand deceased donor donation, split organ donation, paired donor exchange, national sharing models and greater utilization of expanded criteria donors. Although donation after brain death (DBD) accounts for the majority of deceased organ donors, in the recent years, there has been a growing interest in donors who have severe and irreversible brain injuries but do not meet the criteria for brain death. If the physician and family agree that the patient has no chance of recovery to a meaningful life, life support can be discontinued and the patient can be allowed to progress to circulatory arrest and then still donate organs (donation after cardiac death [DCD]).
In the last 10 years, the number of deceased organ donors has increased nationally by 40%, whereas DCD has increased 10-fold with almost 800 cases of DCD reported in 2008 [1][2][3]. In this study, we examined the pattern of donation and utilization in the US over the past ten years (2000 to 2009) by reviewing the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) database.

MATerIAls ANd MeThOds
We performed a retrospective analysis of OPTN/UNOS database about who were consented for organ donation between January 2000 and December 2009. The retrieved records were then categorized into two time periods-from January 2000 to December 2004 (era 1), and from January 2005 to December 2009 (era 2). The results were based on data reported to OPTN/UNOS as of October 25, 2010. Discard was considered when the organ was recovered but not transplanted. Statistical comparisons were made using χ 2 test. A p value <0.05 was considered statistically significant.

resulTs
There were 68,802 living donors and 71,401    There has also been a change in the demographics of organ donors over the course of this study. As shown in Table 1, a significant increase in the incidence of cardiovascular/ cerebrovascular, as cause of death, was increased from 38.1% in era 1 to 56.1% in era 2 (p<0.001); there was a concomitant decrease in the incidence of death due to head trauma (34.9% vs. 48.8%). The proportion of donors older than 64 years almost doubled from 6.9% in era 1 to 11.3% in era 2 (p=0.03). The num-ber of donors with a body mass index (BMI) >35 kg/m 2 also increased from 6.8% to 11.2% (Fig. 2). Figure 3 shows the pattern of the overall number of organs recovered and transplanted from 2000 to 2009. The total number of organs recovered and transplanted increased from era 1 to era 2. There were 146,923 organs recovered in era 1 which increased by 41% to a total of 207,366 in era 2. On the other hand, the total number of organs transplanted increased by 37% from 133,508 in era 1 to 183,991 in era 2. However, the overall discard rate increased by 41% from 13,164 in era 1 to 19,516 in era 2 ( Table 2). This increase in discards was especially more prominent in DCD group which rose by 374% from 440 in era 1 to 2089 in era 2. The discard rate for livers, and kidneys increased by 31%, and 68%, respectively, especially in the DCD group. We noted 78% increase in the discarded DCD livers and 1210% in DCD kidneys.  We also observed a very similar pattern of organ recovery, transplanted and discarded in 11 UNOS regions, comparing era 1 with era 2 (Fig. 4). The number of organs recovered, and transplanted increased in all regions ( Fig.  4A and 4B) from 2%-42%, and 1%-36%, respectively. On the other hand, the discards increased by 20%-70% in different region, except for regions 1 and 6 where discards decreased by 12%, and 10%, respectively ( Fig.  4C and 4D).

R. F. Saidi
In addition to recent stagnant growth in overall donors, the percentage of standard criteria donor (SCD) steadily declined from 78% in 1998 to about 65% in 2007 [1]. This decline can be attributed to increases in the number and percentage of ECDs and DCDs [1]. The shift in the distribution of recovered kidneys from SCD to ECD and DCD impacts utilization, since DCD and ECD kidneys have higher rates of discard. The observed increase in DCD also explains, in part, the fewer organs per donor that are recovered and transplanted overall, and the current state of less than 3.75 organs transplanted per donor (OTPD); the OTPD was 2.08 for DCD, 1.72 for ECD and 3.63 for SCD in 2007 [11][12][13]. In this study, we found that the number of organs recovered and transplanted per donor decreased form 4.5 and 4.1 in era 1 to 4.3 and 3.8 in era 2, respectively.
Compared to the year 2006, in 2007, 299 fewer SCD kidneys were transplanted; there was an increase of 163 DCD non-ECD transplants [1][2][3][4][5]. Consistent with the goals set by HRSA for DCD development, the percentage of donors from DCD continues to increase. There has been a total increase in the percentage of donors that are categorized as DCD, from 8% in 2006 to 9.8% in 2007; the number and percentages of DCD liver and kidney transplants continue to increase substantially [1][2][3][4][5][6][7][8][9][10][11][12]. We encountered parallel changes in our study; the number of DCD donors increased markedly from 3.5% in era 1 to 9.3% in era 2. On the other hand, we noted a decrease in living donation and only a slight increase in the number of DBD.
Our analysis showed a significant change in the diagnosis leading to donation over the last 10 years. There was a shift from trauma donors to donors with cardiovascular/cerebrovascular disease in the US. The portion of donors who died of trauma decreased from 48.8% in era 1 to 34.9% in era 2 (Table 1). On the other hand, donors who died of cardiovascular/cerebrovascular disease rose from 38.1% in era 1 to 56.1% in era 2. The UNOS data from 1995 shows that 48.8% of donors died of trauma and that this number decreased to 34.9% in 2008 [5].
Although the total number of donors increased by 25% from era 1 to era 2, the number of DBD peaked in 2006 and constantly decreased since (Fig. 1). The main increase in the number of donors was in DCD group which raised 230%, comparing era 1 to era 2. At the same time, the number of DBD increased by only 17%, comparing era 1 and era 2. Whether this represents addition of donors who would not have ever progressed to brain death or an exchange for DCD in cases that would have previously followed a DBD pathway, remains uncertain. If the latter is the case, this may reflect a change in clinical practice in which withdrawal of support is offered earlier in the patient's course-before brain death occurs. Saidi, et al. [13], identified a significant change in resuscitative practices over time, with a striking rise in new surgical interventions such as craniostomy, craniotomy, cooling, etc., that have the potential to intercede in the progression to brain death. These interventions were strongly associated with intent to donate via DCD. The lesser likelihood of making the diagnosis of brain death in these patients provides a plausible explanation for at least part of the stagnant growth of DBD compared with DCD in our program and in the region.
The portion of donors older than 64 years increased from 6.9% in era 1 to 11.3% in era 2 (p=0.03). The number of donors with BMI >35 kg/m 2 was also increased from 6.8% to 11.2%. As the result of increase in DCD, more donors with comorbities and elderly donors, we also noted a dramatic increase in the discard rates; the overall discard rate increased by 41% from 13,411 in era 1 to 19,516 in era 2. This increase in discards was especially prominent in DCD group which rose by 374% from 440 (20.9%) in era 1 to 2089 (24.9%) in era 2. The discard rate for livers and kidneys increased by 31% and 68%, respectively, especially in DCD group-78% for DCD livers and 1210% for DCD kidneys.
The data on DCD organ recovery rates were compounded by the large and ever-growing literature indicating that organs recovered from DCD donors may have a compromised outcome post-transplant [14,15]. Allograft and patient survival of DCD kidneys are reported to be similar to DBD kidneys; however, DCD kidneys have been associated with increased resource utilization [16]. For DCD livers, there is a high rate of biliary strictures that have been attributed to the period of warm ischemia that occurs between withdrawal of donor life support and organ preservation. This leads to a reduction in graft survival and an increase in the need for re-transplantation [15]. For heart, lung, and pancreas recipients there is little utilization of DCD organs, though some centers have reported acceptable outcomes using DCD pancreata [17][18][19].
The transplant community should come up with solutions to deal with problems such as optimal identification and management of DCD donors and more investment in live donation. There should also be emphasis on measures to improve the quality of organs like pumping the organs or resuscitation of DCD organs [20,21]. Organ allocation and distribution has its roots in the heterogeneous and somewhat arbitrary geographic boundaries that determine the current donation service areas (DSA) and UNOS regions. This has led some to call for broader allocation units to make distribution more equitable and not only based so tightly on the geography. This can potentially lead to better utilization of organs and also decrease the discard rate [22]. Our study also showed that there was a wide variation in different regions regarding changes in or organ recovery (2%-42%), transplantation (1%-36%) and discards (10% to 70%). The transplant community and policy makers should consider every precaution to safeguard the donor pool and prevent the decay of organ quality in favor of quantity.